Photochromic technology
Photochromic is the term used to describe a substance, now including the transitional window film, that changes its colour composition when it is exposed to electromagnetic radiation, most often the sun, but sometimes also for other industrial applications.
This technology is now most commonly used for ‘transitional’ glasses that react to sunlight, creating a tint in the lens. The process has been limited to solid glass and plastics until recently. By combining nano-ceramic and photochromic technology, the ability to adjust the rejection of the sun’s rays according to varying levels of sunlight has now been achieved.
How it works
Our Photochromic film uses a precious metal magnetron spluttering technique & a nano ceramic particle coating technology. For IR blocking, this is achieved by silver reflective. This will result in a slight temperature rise of the glass by 3-5 degrees.
- When exposed to UV light, Photochromic film molecules change to create a darkening, tinting effect
- The molecules to change their shapes/structure to absorb light when they are exposed to UV radiation.
- The Transitional Window Film darkens to a tint that blocks out about 85% of the harmful UV radiation within 10 minutes
- When fully tinted, the transitional window film blocks out up to 99.5% of the UV radiation
- When the UV light goes away, the molecules in the film return to their original state and the tint diminishes
The photochromic chemical process that takes place for the tinting effect
Once exposed to sunlight/UV radiation, an oxidation-reduction reaction takes place in the photochromic layer, which is 1 – 30 microns thick. During this process, chlorine is oxidized to produce chlorine atoms and an electron. Below is the formula of chemical reaction process:
〖Cl〗^-→Cl+ e^-
The equation below indicates the free electron being transferred to silver ions that produce silver ions:
〖Ag〗^++ e^- →Ag
As these atoms cluster together, they cause the lens to darken, blocking the harmful UV radiation.